Niche construction mediates climate effects on recovery of tundra heathlands after extreme event

plots. Furthermore, the speed of vegetation recovery was very low and close to stagnated about four years after the extreme event took place (Fig 2b). Thus, we found hardly any biomass in extreme event plots at the end of the study (Figs 3b and 4b). Extreme event plots showed also a slight decrease in total biomass with increasing continentality index, whereas control plots showed no such effect (Figs 3 and 5a, S2 Table). Mean biomass of subordinate species alone (excluding E. nigrum) showed no difference between extreme event and control plots (Figs 3 and 5a, S2 Table). However, control plots had overall higher biomass of subordinate species in continental than coastal sites (Fig 5a), whereas Fig 3. Mean biomass (g/m2) of dwarf shrubs (excluding E. nigrum) (i.e. D.shrubs), Forbs/grasses and only E. nigrum registered in 2019 along the climatic gradient (i.e. continentality index). The mean is presented with 95% confidence intervals. a) Control plots, and b) extreme event plots. https://doi.org/10.1371/journal.pone.0245929.g003 Fig 4. Sample plot photographs taken during summer 2018. a) Control plot, and b) Extreme event plot where the vegetation was removed 9 years ago. Take note of the low plant biomass and bare soil in the extreme event plot. https://doi.org/10.1371/journal.pone.0245929.g004 PLOS ONE Niche construction effects on tundra after extreme event PLOS ONE | https://doi.org/10.1371/journal.pone.0245929 February 4, 2021 8 / 14